Method and apparatus for burning of argillaceous material



May 29, 1.934. 1,960,572'

METHOD 'ANDAPPARATUS FOR BURNING oF ARGI-LLAcEoUs MATERIAL F. W. BUTTERWORTH ET AL.

12A Sheets-Sheet, l

I LUN' Fildv De. 27, 1932 lmim'w .HwilllllIIIIHHIIIIII'H May 29 1934- F. w. Bu'rTERwoRTH Er Al. 1,960,572

METHOD AND APPARATUS FOR BURNING OF ARGILLACEOUS MATERIAL 2 Sheets-Sheet, 2

Filed D60. 27. 1952 Patented May 29, 1934 METHOD AND APPARATUS FOR BURNING 0F ARGILLACEOUS MATERIAL Frank w. utterwtth and Irl n. oline, Danville, Ill., assignors to Western Brick Company, Danville, Ill., a corporation of Illinois Application December 27, 1932, Serial No. 648,852

1a claims.

'I'his invention relates to a new and improved method and apparatus for the burning of argillaceous materials, and more particularly for burning such material where expansion takes place during the burning operation.

Certain methods of expansively burning argillaceous materials have recently b een developed in which the expansion is mainly, if not entirely, toward the center or inwardly of the blank or mass of material being treated. In order to cause this expansion to take place it is necessary to coniine the material and prevent or limit outward expansion.A When a smooth dense outer surface is desired it has been found important to have the blank closely engage the-wa1ls of the container before burning. Any usual means, such as sand, may be used to prevent adhesion of the blank to the container.

The use of what is known in the ceramic art as the tunnel kiln has been found to be the most desirable method of accomplishing this expansive burning under the process described. The essential principle of the tunnel kiln is that the Iiring` zones are stationary and the ware to be burned is placed on cars having a re clay, or other refractory super-structure and these cars are pushed through the tunnel. In every instance, the various ring zones remain stationary and the ware travels through the various firing zones. The use of a sand seal insulates the bottom of the tunnel from the top so that the running gears, wheels and axles of the car are kept cool, whereas the superstructure and the ware contained thereon can be brought up to a sufficiently high matur- .ing temperature without affecting the metal portions of the conveying cars.

It is found necessary in practice, due to the rapid increase in temperature necessary to accomplish the expansive burning of -argillaceous materials, to employ high temperature resisting alloys because up to the present, no other refractory material such as re clay or carborundum has been found which will withstand as rapid heating without showing distressingcracks, and deteriorating and breaking down rapidly.

In using a high temperature resisting alloy, it is found in actual practice that after the burning has been accomplished and cooling commences, that there is VaI-radical diierencein the rate of contraction during this cooling process between the metal container and the ware contained therein, the metal contracting considerably more than the ware. The result of this is the setting up of cooling strains which damage the ware.

We have therefore devised a means by which the metal containing apparatus will be knocked down immediately after the ware has been matured and the cooling commences. The metal 'confining apparatus is so arranged with crossbars that so'long as these cross-bars remain in place, the confining apparatus is rigid and maintains its original shape and dimension. Immediately, however, that the burning process is complete, by the use of trip bars projecting into the tunnel at fixed places, the travel o-f the car engages the cross-bars with these trip bars in such a way as to release them and this in turn releases all strain upon the ware caused by the contraction of the metal in cooling.

It is an object of the present invention to provide a new and improved method and apparatus for the expansive burning of argillaceous materials.

It is a further object to provide a method in which outward expansion of the material is prevented during the burning and in which the material is unrestrained during the cooling and annealing..

-It is an additional object to provide apparatus for restraining expansion during burning together with means operable within the kiln to release said restraint.

It is -also'an object to provide means for automatically releasing the restraint at a predetermined point in the burning process.

Other and further objects will appear as the description proceeds.

We have shown -a preferred embodiment of our invention in the accompanying drawings, in

Which- Figure 1 is a transverse section of a tunnel kiln, car, and container;

Figure 2 is a perspective View of a container locking bar;

Figure 3 is a perspective view of an intermediate container section; l 4

Figure 4 is a fragmentary section on an enlarged scale showing a container corner with the locking bar thereon;

Figure A5 is a side elevation, partly in section, of `a kiln'car with containers mounted thereon; and

Figure 6 is a plan view of the container assembly. v

In the drawings, a usual type of tunnel kiln is shown having the side walls l1 and 12 and arched roof 13. The section of the kiln shown is the cooling zone and therefore no heating means are shown. The kiln car 14 is shown ontracks l5, the

car carrying the refractory oor 16 and the rei furactory blocks 17 and 18 having portions 19 and 20 extending ,into recesses 21 and 22 in the side walls of the kiln. The specific design of the kiln and kiln car form no part of the present invention and any desired form of seal may be used to prevent the heat in the kiln proper from affecting the Wheels and supporting structure of the car.

The metal container sections 23 are supported upon columns of refractory brick 24 as best shown -in Figures 1 and 5. As shown in Figure 1 the in Figure 5 to permit a maximum contact be` tween the heated kiln gases and the cont-ainer surfaces.

The container sections 23are so placed as to form a continuous wide, flat metallic enclosure for the ceramic material being treated. The sections have vertically extending portions 26 which are placed to form the sides of the enclosure. The top of` the enclosure is formed by means of fiat plates 27, one for each container section, these plates being equal in size to the bottom portions of the members 23. The outer edges of the plates 27 rest on the upper edges of the vertical portions 26 of the sections 23,. The inner edges of the plates rest on the ware in the containers.

The locking lugs 28 are formed at the upper edges of the vertical portions 26 of the container sections, as best shown in Figure -3. These lugs 28 have the lower rounded corners 29 and the upper fulcrum extension 30. The locking bars 31, as b est shown in Figure 2, are formed in inverted T section and have the downwardly extending portions 32 and hooked ends 33. The ends of the bars are also formed with the ears 34 for engagement by the trip bars 35, shown in Figure 1. The trip bars 35 extend through openings 36 in the kiln walls and are guided in members 37 carried by the steel framework 38 of the In the use of the apparatus shown, the container sections 23 are put in place on the carand the blanks to be heated are placed therein. The top plates 27 are next put in place and a lock bar 31 is put across eachpair of sections 23 with its ends 33 hooked under the lugs 28. The adjacent edges of the members 23 and plates'27 are spaced sufficiently when locked in assembled relation so that the edges will not engage and cause buckling when the members and plates expand under the heat in the kiln. The bars 31 also expand under the heat in the kiln.

The container sections may be soclosely placed, however, that there is little opportunity for the ware Within them to expand through the cracks between sections. This is particularly true since expansion of the ceramic material does not take place until there has been a considerable rise in temperature both in the container and in the material. No partitions have been shown in the containers. With some types of ware to be heated, no partitions may be necessary, the blanks of ceramic material having their surfaces treated to prevent adhesion. With other types of ware it may be desirable to supply partitions such as metal plates of the same alloy used in the containers. These partitions may be held in place by the blanks and their spacing will bedetermined by th'e size of the blanks. The kiln cars are pushed through the kiln in close contact with each other so that the container is continuous and no end plates are needed.

The cars pass through the various heating held together by the locking bars so that any outward expansion of the ceramic blanks being treated is prevented or limited. As the cars reach the cooling section of the kiln the trip bars 35 engage the ears 34 on the lockingbars 31 and as the cars move forward this engagement causes the bars. 31 to tilt about the upper portion 30 of the locking lug 28 as a fulcrum. The portions 33 of the bars 31 move around the arcuate surfaces 29 of the lugs 28. Since the fulcrum portions 30 of the lugs 28 are above the level of the top plates, the trip bars 35 will tilt the locking bars 31 until their ends clear both the locking lugs and the top plates so that the container sections are not drawn together by any contraction of the locking bar upon cooling. The sidesof the container sections will move outward upon release suiiiciently so that there is no possibility of the locking bar swinging back into locking position after it clears the tripping bars.

While we have shown a preferred form of construction this is to be taken as illustrative only as the construction is capable of modification and releasing the restraint and cooling the expanded i material.

2. The method of burning argillaceous material which comprises, forming a blank of such material, the blank having cavities therein, fitting restraining means closely about the blank, heating the blank to a temperature at which it expands into the cavities and into intimate contact with the restraining means, removing the restraining means, and slowly cooling the expanded material.

3. Apparatus for expansively burning argillaceous material comprising, a restraining container adapted to closely t the material to be burned, means for locking it upon the material and means for releasing the container from locked engagement with the material.

4. Apparatus for expansively burning argillaceous material comprising, a container consisting of a plurality of elements adapted to enclose the material to be burned, means for holding the plurality of container elements against expansion, and means for releasing said holding means.

5. Apparatus for expansively burning argillaceous material comprising, a container consisting of a plurality of elements, certain elements including side and bottom portions, other elements comprising top portions, and removable locking bars holding the elements in assembled relation.

6. Apparatus for `expansively burning argillaceous material comprising, a container consisting of a plurality of elements, certain elementsancluding side and bottom portions, other elements comprising top portions, and removable locking bars holding the elements in assembled relation, said bars extending across the top portions and having downwardly extending ends engaging the side portions.

7. Apparatus for expansively burning argillaceous material comprising, a container consisting of a plurality of elements, certain elements including side and bottom portions, other elements comprising top portions, and removable locking bars holding the elements in assembled relation, said bars extending across the top portions and having downwardly extending ends engaging the side portions, the side portions having lugs engaged by the bar ends to prevent upward movement of the bars.

8. Apparatus for expansively burning argillaceous material comprising, a tunnel kiln having zones of diierent temperature, a car for carrying material through the kiln, a sectional container carried by the par, locking means for holding the sections in assembled relation to restrain expansion of the material, and means located Within the kiln for releasing the locking means when the car reaches a predetermined temperature zone in the kiln.

9. Apparatus for expansively burning argillaceous material comprising, a tunnel kiln having zones of diiferent temperature, a car for carrying material through the kiln, a sectional container-carried by the car, the container being divided in sections both longitudinally and transversely of the car, locking means for holding the sections in assembled relation to restrain expansion of the material, and means located within the kiln for releasing the locking means when the car reaches a predetermined temperature zone in the kiln.

10. Apparatus for expansively burning argillaceous material comprising, a tunnel kiln having zones of different temperature, a car for carrying material through the kiln, a sectional steel alloy container carried by the car, locking means for holding the sections in assembled relation to restrain expansion of the material, the steel sections being assembled in such relation as to permit heat expansion of the sections without deformation ofthe container, and means located within the kiln for releasing the locking means when the car reaches a predetermined temperature zone in the kiln.

11. Apparatus for expansively burning argillaceous material comprising, a tunnel kiln having zones of different temperatures increasing and then decreasing, a car for carrying material through the kiln, a sectional container carried by the car, locking bars extending across the tops of said sections and having downwardly extending portions engaging sides of the sections, and

means in a zone of decreasing temperatures of the kiln for releasing said locking bars.

12. Apparatus for expansively burning argillaceous material comprising, a tunnel kiln having zones of diierent temperatures increasing and then decreasing, a car for carrying material through the kiln, a sectional container carried by the car, locking bars extending across the 'tops of said sections and having downwardly ex- FRANK W. BUTTER'WORTH. IRL R. CLINE. 

